Feiedeich schubeet



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F. SGHUBERT. SPRING'BAGK FOR BOOKS.

Patented Apr. 11

Fngl.

Photo Llihographcr, Washingion, o c,

UNITED STATES PATENT OFFICE.

FRIEDRICH SOHUBERT, OF ZURICH, SWITZERLAND.

SPRING-BAK FOR BOOKS.

SPECIFICATION forming part of Letters Patent No. 256,245, dated April 11, 1882.

Application filed January 16, 1882.

and more particularlyofaccount-books; and the improvement consists in making the springbacks thereof of an elastic inner part, to which are longitudinally attached strips or ledges of wood or other suitable material, and a covering stitched to the inner part.

The invention is represented on the annexed sheet of drawings, Figure 1 showing perspectively and in open state a book provided with the improved back, Fig. 2 being a view of the back from the outside, while Figs. 3, 4,

and 5 represent sections through the back and part of the book in closed, half-opened, and completely-opened state, respectively.

Similar letters of reference indicate corresponding parts.

In large account-books it is necessary to impart to the outer back or spring-back a satficient stiffness as well longitudinally as transversely, so that on one hand a. deformation of theback may be prevented when the book is placed upright, and that, on the other hand, when the book is opened,the spring-back may force upwardthe inside flexible back in such a manner that the leaves of the book will lie straight, 'so as to allow of their being written on with convenience. In some cases a complete rigidity has been given to such backs by inserting plates of iron into the same.

A spring-back'of the ordinary kind which is stiff enough to keep the book in its proper shape longitudinally will, however, not onlyprevent the book from being opened and closed with facility, but it will have a prejudicial influence on the binding, as when the book is opened or closed the inside back is strained, in consequence whereof the leaves soon become loose, so as toprojectirregularly at the front edge. For the purpose of obviating these inconveniences I construct the springback of a number of strips or ledges of wood, a a, by preference half-round, which are fixed parallel to each other on a sufficiently elastic part, b. This partis made up of several pieces of pasteboard, (two,three, or more, according to the thickness of the book,) of suitable size, and bent into a semicircular form, which are glued together. When the books are very ,strips.

(No model.)

thick it is advantageous to place between them any kind of cloth, leather, or parchment in order toimpart greater strength to the back. Moreover, several elastic strips or hands of steel may be fastened transversely to the inside of the said part I) .by rivets or otherwise, for the purposeof makingitstronger. On the part I) thus prepared the strips or ledges a a, which are by preference made of wood, but which may also consist of some other suitable material, are fixed by gluing or riveting. A portion of the strips, where the title is to be put, having then been worked even, the back is covered with the desired 1naterial-as, for instance, leather or cloth--in such a manner that the same bends around and closely joins each one of the strips a. This covering d is hereupon sewed together with the inner part, b, of the back by stitches passing between the Finally the back may be lined with thin leather or cloth.

The sewing is performed with advantage by means of a sewing-machine having a suitable work-plate and feeding mechanism.

hen a book provided with the described back is opened partly the back expands from its normal semicircular form into a flat form, as shown by Fig. 4. The book being thereupon opened entirely, the back resumes its original form, Fig. 5, or it may even spring inward to a certain extent, so as to insure the proper flattening of the leaves. When the bookis being closed an expansion again takes place, as during the opening of the same. On account of this elasticity the book may be openedand closed with facility and without detriment to its binding; but while the back is resilient in transverse direction, it possesses-longitudinally the full stiffness required to maintain the book in its proper form.

Having thus described my invention,I claim as new and desire to secure by Letters Patent- A spring-back for books, consisting of a resilient inner part, I), exterior longitudinal strips, to a, and a covering, (1, stitched intermediately between the strips totheinner part, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witnesses, this 11th day of November, 1881.

FRIEDRICH SOHUBERT.

Witnesses:

O. Aneusr- WEISSHAAR, A. BRINER. 

